The temporary ‘Progrès’ consortium of two BAM Contractors subsidiary companies and the Belgian branch of Soletanche Bachy France was awarded work package 1 of the project at the end of 2020.
This work package involves a structure beneath the Gare du Nord rail network and two worksite shafts – P5 (on the Rue d’Aerschot side) and P6 (on the Gare du Nord side) – to enable the transit of STIB (Société de Transport Intercommunale de la région de Bruxelles) metro trains.
Both shafts will be built using diaphragm wall of between 1 and 1.2 metres thickness, and will be up to 30 metres deep.
The tunnel beneath the rail tracks is approximately 150 metres, and varies in width from 8.66 metres in its current section to 23.1 metres.
Three-metre diameter tunnels will be bored as lined excavations beneath the station rail tracks. The finished tunnels will be used to drill three sets of jet grouting columns tube-reinforced to a depth of 26 metres. The walls of these secant columns will provide temporary support for the excavation and construction of the metro tunnel beneath the rail tracks of the Gare du Nord station.
A series of jet grouting plugs will also be created between the new and the existing structures, as well as a slab to ensure waterproofing and strutting Shaft P5.
The works should start on March 2021 and be finished at the beginning of 2024.